Friction MCQ Class 8

Friction MCQ Class 8. These 100 Multiple Choice Questions on “Friction” will help you score full marks in your Class 8 Science exam.

Force of Friction

Definition of friction

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Correct Answer: B. A force that opposes motion between two surfaces in contact. This is the basic definition of friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. A ball rolling on the ground and slowing down. Friction acts against the ball’s motion, causing it to slow down and eventually stop. (Friction MCQ Class 8 by Top100MCQ.com)

   

Force of friction

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Correct Answer: C. Friction. Friction is the force that resists the sliding motion of the book. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: A. Friction. The carpet’s surface creates friction against the car’s wheels, slowing it down. (Friction MCQ Class 8 by Top100MCQ.com)

   

Opposing nature of friction

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Correct Answer: B. In the opposite direction. Friction always acts to oppose the motion of an object. (Friction MCQ Class 8 by Top100MCQ.com)

   

Relative motion

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Correct Answer: B. Relative motion. Friction arises when surfaces slide or try to slide against each other. (Friction MCQ Class 8 by Top100MCQ.com)

   

How to measure friction

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Correct Answer: C. By measuring the force required to initiate or maintain motion. The force needed to overcome friction is a measure of the friction itself. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It increases.  A heavier object presses down with more force, leading to increased friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

Spring balance

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Correct Answer: C. Spring balance. A spring balance measures the force required to move an object against friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: A. The extension of a spring is proportional to the force applied. This principle allows the spring balance to accurately measure the force. (Friction MCQ Class 8 by Top100MCQ.com)

   

Factors Affecting Friction

Effect of surface nature on friction

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Correct Answer: B. A rough road. Rough surfaces have more irregularities that create friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. The tabletop has less friction than the carpet. Polished surfaces offer less resistance to motion. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Spreading sand on a slippery road. The sand increases the roughness and thus the friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

Effect of the smoothness of the surfaces

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Correct Answer: B. Smoother surfaces have less friction. Fewer irregularities mean less interlocking and less friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It is reduced significantly. While complete elimination is impossible, smoothing greatly reduces friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

Friction MCQ Class 8

Surface irregularities

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Correct Answer: C. The interlocking of surface irregularities. Even seemingly smooth surfaces have tiny bumps and grooves that catch on each other. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Friction would increase. More irregularities mean more interlocking and greater resistance to motion. (Friction MCQ Class 8 by Top100MCQ.com)

   

Effect of the force of friction

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Correct Answer: C. It increases. Pressing harder increases the contact between irregularities, leading to higher friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. The heavy box has more friction. Its weight presses it harder against the floor, increasing friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

Effect of the nature of the two surfaces

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Correct Answer: B. Yes, rougher surfaces create more friction. Different materials and textures have varying degrees of friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Ice is smoother than the road, offering less friction. The reduced friction makes it difficult to get a grip and walk safely. (Friction MCQ Class 8 by Top100MCQ.com)

   

Static friction

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Correct Answer: C. Static friction. Static friction is the initial resistance that needs to be overcome to start an object moving. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Static friction. The static friction is strong enough to prevent the box from moving initially. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Static friction. It generally takes more force to overcome static friction and start an object moving than to keep it moving. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It is replaced by sliding friction. Once the object is in motion, sliding friction takes over. (Friction MCQ Class 8 by Top100MCQ.com)

   

Sliding friction

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Correct Answer: C. Sliding friction. This friction occurs while the object is in motion, sliding against the surface. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Sliding friction. It’s usually easier to keep an object moving than to start it moving from rest. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Because sliding friction is less than static friction. Once the initial static friction is overcome, less force is needed to maintain the motion. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. It increases. Rougher surfaces create more resistance to sliding. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. A car braking to a stop. The brake pads create sliding friction against the wheels, slowing the car down. (Friction MCQ Class 8 by Top100MCQ.com)

   

Friction: A Necessary Evil

Advantages of friction

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Correct Answer: B. It prevents our feet from slipping. Friction provides the grip needed for controlled movement. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. It provides grip between the tires and the road. This grip is essential for acceleration and turning. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. The pen would slip and we couldn’t write. Friction is necessary for the pen to leave a mark on the paper. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. By using friction to slow down the wheels. The brake pads create friction against the wheels, reducing their speed. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It provides the grip to strike the match. Friction ignites the match head when it is struck against the rough surface. (Friction MCQ Class 8 by Top100MCQ.com)

   

Disadvantages of friction

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Correct Answer: B. It produces heat, wasting energy. This heat generation can lead to wear and tear in machines. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It makes them less efficient due to energy loss. Overcoming friction requires extra energy, reducing efficiency. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Due to friction causing wear and tear. Constant rubbing leads to damage and wear. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It slows them down. Friction acts against motion, reducing speed. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. To reduce friction and wear. Oil acts as a lubricant, minimizing friction between moving parts. (Friction MCQ Class 8 by Top100MCQ.com)

   

Increasing and Reducing Friction

Methods to increase friction

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Correct Answer: B. To increase friction for better grip. The treads provide more contact with the road, improving traction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To increase friction and prevent slipping. The spikes dig into the ground, providing extra grip. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To increase friction for a better grip. Chalk absorbs moisture and increases the friction between their hands and the equipment. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To increase friction and remove material. The rough texture of sandpaper creates enough friction to wear away the surface. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To increase friction and prevent slipping. The mats provide a textured surface for better grip. (Friction MCQ Class 8 by Top100MCQ.com)

   

Methods to reduce friction

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Correct Answer: C. To reduce friction and noise. The oil lubricates the hinge, allowing it to move more smoothly and quietly. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It reduces friction and makes pedaling easier. Grease acts as a lubricant, reducing friction between the moving parts of the chain. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To reduce friction and wear, improving efficiency. Lubricants like oil reduce friction between moving parts, leading to less wear and tear and better fuel economy. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To convert sliding friction into rolling friction, reducing friction overall. Ball bearings allow parts to roll over each other, which has less friction than sliding. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. The wheels reduce friction. Rolling friction is less than sliding friction, making it easier to move the box. (Friction MCQ Class 8 by Top100MCQ.com)

   

Lubricants

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Correct Answer: C. Substances that reduce friction between surfaces. Lubricants create a smooth layer between surfaces, reducing contact and friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: D. Sandpaper. Sandpaper is abrasive and increases friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. By creating a thin layer between surfaces, preventing direct contact. This separation reduces the interlocking of surface irregularities. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Different machines have different requirements for friction and lubrication. Factors like temperature, pressure, and the types of materials involved influence the choice of lubricant. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It will attract dust and dirt, potentially causing damage. Excess lubricant can become a problem by trapping contaminants. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Air creates a cushion between surfaces, reducing friction without the need for oil or grease. This is useful in situations where traditional lubricants are not suitable. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. To reduce friction and make pedaling easier. A well-lubricated chain reduces the effort required for cycling. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. They reduce the contact between surfaces, preventing damage from friction. Less friction means less wear and tear, extending the life of the machine. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. No, lubricants can only reduce friction, not eliminate it completely. Some friction will always exist between surfaces, even with lubrication. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. To maintain low friction and prevent wear and tear. Regular lubrication ensures smooth operation and prolongs the life of the machine. (Friction MCQ Class 8 by Top100MCQ.com)

   

Wheels Reduce Friction

Rolling friction

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Correct Answer: C. Rolling friction. Rolling friction is the resistance encountered when an object rolls over a surface. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Because rolling involves less surface area in contact. This reduced contact area leads to less interlocking and friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. It reduces friction, making it easier to pull. The wheels convert sliding friction to rolling friction, which is easier to overcome. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To reduce friction and make it easier to move the object. Rollers reduce the contact area and friction between the object and the ground. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It would be much harder to move due to increased friction. Sliding friction is greater than rolling friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

Advantages of rolling friction over sliding friction

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Correct Answer: B. Rolling friction. Rolling friction is generally much less than sliding friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Wheels reduce friction, improving efficiency and speed. By reducing friction, cars can move faster and use less fuel. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. To reduce friction and improve efficiency. Reducing friction leads to less wear and tear, lower energy consumption, and better performance. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Bicycle wheels reduce friction, making movement easier. The rolling friction of the wheels is much less than the sliding friction of your feet on the ground. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Machines would require more energy to operate and wear out faster. Increased friction leads to higher energy consumption and increased wear and tear. (Friction MCQ Class 8 by Top100MCQ.com)

   

Ball bearings

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Correct Answer: C. Small, smooth balls used to reduce friction in machines. Ball bearings convert sliding friction to rolling friction, reducing friction overall. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. By separating surfaces with small, rolling balls. The balls allow parts to roll over each other instead of sliding, reducing friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. In bicycles, ceiling fans, and other machines with rotating parts. Ball bearings help these parts rotate smoothly and with less friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. They reduce friction, leading to less wear and tear and improved efficiency. By reducing friction, ball bearings help machines last longer and use less energy. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. The machine will become less efficient and may overheat due to increased friction. Damaged ball bearings can increase friction, leading to problems like overheating and reduced performance. (Friction MCQ Class 8 by Top100MCQ.com)

   

Fluid Friction

Frictional force by fluids

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Correct Answer: B. Friction that occurs when an object moves through a fluid. Fluid friction is the resistance experienced by objects moving in liquids or gases. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Any substance that flows, including liquids and gases. Fluids take the shape of their container and can exert friction on objects moving through them. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Because fluids exert a force against the motion of the object. This opposing force is the fluid friction or drag. (Friction MCQ Class 8 by Top100MCQ.com)

   

Drag

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Correct Answer: C. Drag. Drag is the common term for the frictional force experienced by objects moving through fluids. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To reduce drag and improve efficiency. The streamlined shape minimizes the resistance from the air, allowing the plane to fly more efficiently. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It slows them down. The water creates resistance (drag) against the swimmer’s body, reducing their speed. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To reduce drag and make flying easier. The streamlined shape helps birds minimize air resistance during flight. (Friction MCQ Class 8 by Top100MCQ.com)

   

Factors affecting friction in fluids

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Correct Answer: D. The speed, shape, and the nature of the fluid. All these factors influence the amount of drag. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Higher speed creates more drag. As the object moves faster, it encounters more resistance from the fluid. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. It increases drag, opposing the force of gravity. The parachute’s large surface area increases air resistance, slowing the descent. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. A more streamlined hull reduces drag and increases speed. By minimizing water resistance, the boat can move faster through the water. (Friction MCQ Class 8 by Top100MCQ.com)

   

Shapes of objects moving in fluids

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Correct Answer: B. To reduce drag and improve fuel efficiency. The smooth shape minimizes air resistance, allowing the car to use less fuel. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. It reduces drag, allowing them to fly faster and use less fuel. The streamlined shape minimizes air resistance, improving efficiency and speed. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. To reduce drag and swim more efficiently. The streamlined shape minimizes water resistance, allowing fish to swim faster and use less energy. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. They would experience more drag, reducing speed and fuel efficiency. The increased air resistance would make the car less efficient and slower. (Friction MCQ Class 8 by Top100MCQ.com)

   

Keywords

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Correct Answer: B. Friction. This is the fundamental definition of friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Lubricants. Lubricants like oil and grease reduce friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Fluid friction. This is the resistance experienced by objects moving in liquids or gases. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Drag. Drag is another term for fluid friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Interlocking. This interlocking contributes to friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: A. Ball bearing. Ball bearings reduce friction by converting sliding to rolling. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Rolling friction. This type of friction is generally less than sliding friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: C. Sliding friction. This occurs when two surfaces are in motion relative to each other. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: A. Static friction. This is the initial friction that needs to be overcome to start an object moving. (Friction MCQ Class 8 by Top100MCQ.com)

   

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Correct Answer: B. Magnetic friction. This is not a real type of friction. (Friction MCQ Class 8 by Top100MCQ.com)

   

Most Asked Important Questions on Friction Class 8

What is friction?

Friction is the force that opposes the relative motion between two surfaces in contact.

What are the factors affecting friction?

The factors affecting friction are the nature of the surfaces in contact, the state of smoothness of those surfaces, and how hard the two surfaces press together.

What are the types of friction?

Static friction, Sliding friction and Rolling friction

What are the ways to increase friction?

Friction can be increased by making a surface rough. For example, the soles of shoes and the tires of vehicles are patterned to increase friction.

What are the ways to reduce friction?

Friction can be reduced by using lubricants or by using ball bearings.

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